SpaceX has landed a rocket on a floating barge in the ocean for the second time.

Before its first successful landing in April, the company tried and failed multiple times to perch a Falcon 9 rocket on a barge. The company didn't expect things to turn out differently this time.

That's because of the circumstances surrounding this mission. This one placed a Japanese communications satellite into a very high orbit. Because of the destination, the rocket's re-entry was a lot faster and a lot hotter than previous landing attempts.

SpaceX CEO Elon Musk gave a successful landing "maybe even" odds but didn't seem too worried about the potential for failure. He said the team would learn a lot either way.

Musk jokingly tweeted his company "may need to increase the size of [the] rocket storage hangar."

SpaceX is aiming to commercialize spaceflight, and being able to land and re-use rockets would save a ton. It currently costs NASA about $10,000 per pound to put something into orbit. SpaceX says it can do it for less than $4,000 per pound, even for high orbits.

All of these efforts are eventually supposed to lead to sending a rocket to Mars by 2018.